1. Field of the Invention
The invention relates to a continuous in line sampling device for obtaining a representative sample of dry freely flowing material within a manufacturing or transported stream.
2. Prior Art
In the manufacturing of dry particulate materials, it is frequently necessary for quality control purposes to determine by physical or chemical analysis, the quality of small samples. Obviously, very small deviations from specification, in the analysis, can have profound effects on decisions regarding the value or acceptability of the material. A critical step in providing an accurate analysis of such material is to obtain a representative sample.
A sample is usually taken from a feed stream of material in free fall as it passes through a relatively large pipe or chute. Since particulate matter may segregate as it passes through a pipe or chute, for instance, because of differences in particle size or particle density, it is advantageous to obtain a representative sample across the entire cross-section of the sample stream. Obtaining such a sample is the function of a primary sampling device.
Sampling devices are commercially available in a variety of designs.
U.S Pat. No. 2,405,486, for instance, discloses a sampling machine comprised of a movable cone seated on a stationary cone in a nested relationship each cone having a plurality of openings forming splitters. The movable cone having control rods for fully aligning or partially aligning the splitters of the cones and the size of the splitters.
A random sampling machine disclosed as having no moving or rotating parts is described in U.S. Pat. No. 2,405,951 to Herrold. The sampler is said to provide a desired percentage of a material that is selected at random. The sampler as disclosed comprises a mixing chamber having a plurality of concentric conical material-deflecting plates (which may be of differing diameters) alternately concave upward and downward and having staggerd openings for deflecting the falling material in a random manner. The splitting of the proportional sample disclosed in the patent is accomplished after the material leaves the last plate and just prior to its entering a hopper.
It is an object of the present invention to provide a sampler which is simple to construct, involves no moving or rotational parts and which directly provides a small representative sample of the material being sampled.